Computing, communications, switching and interconnection are technical fields which have demonstrated both applicability and need for optics and optical devices. In these technical fields, one class of device which is needed is an optical logic device. For the optical logic device, data or information carrying signals incident on the device control the state of the device in such a way that some Boolean function or combination of Boolean functions is peformed on the incident signals.
Nonlinear Fabry-Perot etalons have been suggested as all-optical devices which can provide optical logic functions. See S. D. Smith, Applied Optics, Vol. 25, No. 10, pp. 1150-64 (1986) and H. S. Hinton, IEEE Journal on Selected Areas in Communications, Vol. 6, No. 7, pp. 1209-26 (1988). One drawback to the use of nonlinear Fabry-Perot etalons in high speed operation is that incident controlling signals such as clock and data signals must be separated in wavelength so that one wavelength correponds to an absorption peak of the nonlinear material in the etalon. Such a limitation is necessary to permit switching or tuning the nonlinear Fabry-Perot etalon between transmissive and reflective states. As a result of this method of operation, the input wavelength is different from the output wavelength thereby excluding the possibility of cascading these devices one after the other. While required wavelength difference pose significant limitations, it cannot be avoided that other limitations arise because temperature variations cause the etalon to undergo changes with respect to location of resonance peaks for the cavity. In turn, the etalon may or may not be responsive to input optical signals. Moreover, intensity variations of the incident signals can cause the nonlinear Fabry-Perot etalon to change state in a haphazard manner of not at all.